1. Field of the Invention
The invention relates to a fuel retention monitoring system for a pressurized hydrogen storage tank on a vehicle and method of using such a system.
2. Background Art
Energy management is a concern for vehicle manufacturers who are trying to achieve improved energy efficiency for their vehicles. Concurrently, vehicle manufacturers are exploring options of alternate fuel systems to petroleum-based liquids. When such alternate fuel systems require hydrogen as a fuel, storage of hydrogen is done conventionally in pressurized storage tanks on board the vehicle. The storage tanks receive and dispense hydrogen gas through a series of connections attached to the pressurized hydrogen storage tank. These connections offer opportunities for undesirable loss of hydrogen gas when they become loosened through vibration, repeated thermal expansion and contraction or other mechanisms. The fuel system loses efficiency when the hydrogen escapes. Early recognition of the loose connections would be advantageous to retaining the energy efficiency of the vehicle.
Current signaling methods for loss of hydrogen from the connections are relatively insensitive because the hydrogen is diluted in the large volume of air surrounding the tank. At relatively low concentrations of hydrogen, sensors have lower signal-to-noise ratios. This leads to the possibility of false positive signals that may inconvenience the operator of the vehicle.
What is needed is a more sensitive fuel retention monitoring system for a pressurized hydrogen storage tank on a vehicle while having the monitoring system produce fewer false positive signals.